A safety filling device of this class has become known from DE-A 41 06 906. The prior-art safety filling device is arranged in the area of the filling space of the anesthetic evaporator and is used to fill in a liquid anesthetic from a storage container. To do so, the end cap of a flexible, coaxial line section, which has a filling channel for filling in the liquid anesthetic and a ventilation channel for compensating the filling volume in the storage container, which changes during filling or emptying, is screwed onto the neck of the storage container. The other end of the line section is provided with a filling adapter for fastening to an insertion opening of the safety filling device. A filling channel and a ventilation channel are also located at the insertion opening. A storage container with a flexible line section screwed onto it for filling an anesthetic evaporator is shown in, e.g., FIG. 2 of DE-A 41 06 756. Before the filling adapter is pushed into the insertion opening, a closing slide, which shuts off the device-side filling channel and the ventilation channel within the insertion opening, is first removed, after which the filling adapter is pushed in, and the filling channels and the ventilation channels are brought into alignment in the operating position. A closing element in the form of a button performing stroke movements with a shut-off valve is located in the device-side filling channel, and the said shut-off valve is switched into the switched-off position prior to filling, so that no liquid anesthetic feed is possible. For filling, the storage container is turned upside down, and the shut-off valve is then opened by pulling the button, as a result of which liquid anesthetic will flow into the filling space of the anesthetic evaporator via the filling channel as a consequence of the force of gravity, while gas flows from the filling space into the storage container via the ventilation channel to compensate the decreasing filling volume in the storage container. After filling, the storage container is lowered, the shut-off valve is closed, and the filling adapter is pulled out of the insertion opening of the safety filling device. The insertion opening is then closed with the closing slide.
It is disadvantageous in the prior-art safety filling device that blocking of filling is possible when the shut-off valve is not in the switched-off position, but is open when the filling adapter is being pushed in. In this case, the filling channel of the flexible line section between the filling adapter and the storage container can be filled completely with liquid anesthetic when the storage container is swung into the upside down position, so that the exchange of liquid between the filling space and the storage container is blocked by air bubbles in the filling channel of the flexible line section, because the shut-off valve is used to initially shut off the device-side filling channel until the filling channel of the flexible line section has been completely filled with liquid anesthetic without liquid anesthetic penetrating into the ventilation channel, after the storage container has been swung into the upside down position. The filling process is then initiated by opening the shut-off valve.
An anesthetic evaporator with a safety filling device, in which a blocking device is provided between a shut-off valve acting as a closing element in the filling channel and a metering member, with which the desired concentration value is set, and with which filling is possible only when the metering member has been switched into the shut-off position, has become known from DE-A 41 08 383.
Even though the prior-art blocking device ensures that the shut-off valve can be actuated only in the switched-off position of the metering member, this does not yet ensure that the shut-off valve will also be located in the closed position when the filling adapter is pushed in, because the switching off of the metering member and filling do not necessarily need to coincide in time. It is therefore possible, e.g., that even though the metering member of the anesthetic evaporator is switched into the closed position after the use of the device in an inhalation anesthesia apparatus equipped with an anesthetic evaporator, filling will be performed only later, e.g., before the next use of the apparatus. It is not guaranteed in this case that the shut-off valve will then still be in the switched-off position.